Central coherence and set-shifting between nonunderweight eating disorders and anorexia nervosa: A systematic review and meta-analysis

Exploring neurocognitive features in adolescents and young adults with anorexia nervosa: Evidence from a longitudinal study

OBJECTIVE

We aimed to evaluate longitudinal changes in set-shifting and central coherence in a predominantly adolescent cohort with anorexia nervosa (AN) and to explore whether these factors predict long-term eating disorder outcomes.

METHOD

Ninety-two female patients with AN (mean age: 16.2, range: 13-21 years) completed neurocognitive tests (Rey Complex Figure Test, Adapted Version of the Wisconsin Card Sorting Test) before and after 12 months of psychotherapeutic treatment (n = 45 Maudsley AN Treatment, MANTRa; n = 47 standard psychotherapy; groups not randomised). Eating disorder severity was assessed at baseline, after 6, 12 and 18 months.

RESULTS

Central coherence (indicated by an increase in the Rey Figure Style Index) and set-shifting (indicated by a reduction in the percentage of perseverative errors) significantly improved over the course of treatment, with similar outcomes across groups. Lower central coherence was associated with higher eating disorder severity. Individuals with lower baseline set-shifting ability tended to have worse eating disorder outcomes in the long-term. However, this trend did not reach statistical significance in a multilevel linear mixed model.

CONCLUSIONS

Neurocognitive difficulties in adolescents and young adults with AN can improve after treatment. Interventions specifically addressing flexibility in thinking and behaviour may contribute to treatment success.

Disentangling cognitive flexibility: a model-based assessment of women with anorexia nervosa

Cognitive flexibility (CF) has been proposed as a potential trait marker in anorexia nervosa (AN), although findings have been inconsistent. To address this inconsistency, we applied a model that distinguishes between three subtypes of CF: task switching, switching sets, and stimulus-response mapping, which we then assessed using a paradigm-based task battery. The aim of the study was to investigate how AN is associated with these three CF subtypes. Thirty-three women with AN and 37 age- and education-matched controls performed a battery of computerized cognitive tasks to assess the three CF subtypes. Compared to the control group, individuals with AN exhibited poorer performance on the task switching and switching sets subtypes, as measured by response time switch cost, but not on the stimulus-response mapping subtype. No differences were found between the groups in response accuracy. Furthermore, switching sets as compared to the task switching and stimulus-response mapping subtypes was found to better explain the differences between the groups. These findings indicate a domain-specific impairment in CF among patients with AN, reflecting deficits observed in subtypes related to the disorder's characteristics, particularly that associated with visual perception. Therefore, CF impairment in AN should not be viewed dichotomously, but rather as a relative impairment that varies depending on the specific CF subtype.

Assessing biomarkers of remission in female patients with anorexia nervosa (REMANO): a protocol for a prospective cohort study with a nested case-control study using clinical, neurocognitive, biological, genetic, epigenetic and neuroimaging markers in a French specialised inpatient unit

BACKGROUND

Anorexia nervosa (AN) is a severe psychiatric disorder associated with frequent relapses and variability in treatment responses. Previous literature suggested that such variability is influenced by premorbid vulnerabilities such as abnormalities of the reward system. Several factors may indicate these vulnerabilities, such as neurocognitive markers (tendency to favour delayed reward, poor cognitive flexibility, abnormal decision process), genetic and epigenetic markers, biological and hormonal markers, and physiological markers.The present study will aim to identify markers that can predict body mass index (BMI) stability 6 months after discharge. The secondary aim of this study will be focused on characterising the biological, genetic, epigenetic and neurocognitive markers of remission in AN.

METHODS AND ANALYSIS

One hundred and twenty-five (n=125) female adult inpatients diagnosed with AN will be recruited and evaluated at three different times: at the beginning of hospitalisation, when discharged and 6 months later. Depending on the BMI at the third visit, patients will be split into two groups: stable remission (BMI≥18.5 kg/m²) or unstable remission (BMI<18.5 kg/m²). One hundred (n=100) volunteers will be included as healthy controls.Each visit will consist in self-reported inventories (measuring depression, anxiety, suicidal thoughts and feelings, eating disorders symptoms, exercise addiction and the presence of comorbidities), neurocognitive tasks (Delay Discounting Task, Trail-Making Test, Brixton Test and Slip-of-action Task), the collection of blood samples, the repeated collection of blood samples around a standard meal and MRI scans at rest and while resolving a delay discounting task.Analyses will mainly consist in comparing patients stabilised 6 months later and patients who relapsed during these 6 months.

ETHICS AND DISSEMINATION

Investigators will ask all participants to give written informed consent prior to participation, and all data will be recorded anonymously. The study will be conducted according to ethics recommendations from the Helsinki declaration (World Medical Association, 2013). It was registered on clinicaltrials.gov on 25 August 2020 as 'Remission Factors in Anorexia Nervosa (REMANO)', with the identifier NCT04560517 (for more details, see https://clinicaltrials.gov/ct2/show/record/NCT04560517). The present article is based on the latest protocol version from 29 November 2019. The sponsor, Institut National de la Santé Et de la Recherche Médicale (INSERM, https://www.inserm.fr/), is an academic institution responsible for the monitoring of the study, with an audit planned on a yearly basis.The results will be published after final analysis in the form of scientific articles in peer-reviewed journals and may be presented at national and international conferences.

TRIAL REGISTRATION NUMBER

clinicaltrials.govNCT04560517.

Weak central coherence, cognitive rigidity and disordered eating in a community sample

Recent evidence has highlighted that a moderate degree of disordered eating has become the norm among the general population. While previous research has demonstrated that individuals with eating disorders exhibit heightened weak central coherence (i.e., attention to detail) and cognitive rigidity, and this plays a key role in the development and maintenance of the disorders, less is known about the relationship between disordered eating and these cognitive styles in subclinical community samples. A community sample of females completed self-report measures of weak central coherence, cognitive rigidity and eating disorder pathology. Unlike previous studies in the area, we first excluded participants with a diagnosis of eating disorder and then confined the analyses to those without clinically significant disordered eating. In line with the clinical literature, we found both cognitive rigidity and weak central coherence to correlate with severity and frequency of disordered eating behaviours and cognitions, suggesting the relationship also exists in subclinical samples. If replicated and expanded upon, these findings may bear important implications for the prevention and early identification of disordered eating in the community.

The role of readiness and confidence to change in the treatment of atypical anorexia nervosa and bulimia nervosa

OBJECTIVE

Atypical anorexia nervosa (AN) is a serious eating disorder that is more common in the population than AN. Despite this, people with atypical AN are less likely to be referred or admitted for eating disorder treatment and there is evidence that they are less likely to complete or benefit from existing interventions. This study examined whether baseline readiness and/or confidence moderated outcomes from 10-session cognitive behavioral therapy among people with atypical AN and bulimia nervosa (BN), and whether the impact of these variables differed between diagnoses.

METHODS

Participants (n = 67; 33 with atypical AN) were a subset from an outpatient treatment study. Linear mixed model analyses were conducted to examine whether baseline readiness and/or confidence moderated outcomes.

RESULTS

People with BN who had higher levels of readiness or confidence at baseline had steeper decreases in eating disorder psychopathology over time. There was no evidence that readiness or confidence moderated outcomes for people with atypical AN.

DISCUSSION

This study suggests that the moderators that have been identified for other eating disorders may not apply for people with atypical AN and highlights a need for future work to routinely investigate whether theoretically or empirically driven variables moderate outcomes in this little-understood population.

PUBLIC SIGNIFICANCE STATEMENT

People with bulimia nervosa with higher readiness and confidence experienced greater decreases in eating disorder symptoms than people with lower readiness and confidence when treated with cognitive behavioral therapy. These findings did not apply to people with atypical anorexia nervosa. Results demonstrate that future work is urgently required to identify helpful treatments for people with atypical anorexia nervosa as well as the variables that have a positive impact on outcomes in treatment for these individuals.

Prospective associations between cognitive flexibility and eating disorder symptoms in anorexia nervosa and bulimia nervosa

This study investigated concurrent and prospective associations between measures of reversal learning and attentional set-shifting and eating disorder symptoms at baseline, 3 months, and 6 months among individuals with anorexia nervosa restricting subtype (AN-R, n = 26), AN binge eating/purging subtype (AN-BP, n = 22), bulimia nervosa (BN, n = 35), and healthy controls (n = 27), and explored whether these associations differed by diagnosis. At baseline, participants completed diagnostic interviews, height/weight measurements, and measures of set-shifting (the Intradimensional/Extradimensional shift task) and reversal learning (a probabilistic reversal learning task). At 3- and 6-month follow-up, participants with eating disorders completed assessments of weight and eating disorder symptoms. A one-way analysis of variance found no evidence that baseline reversal learning and attentional set-shifting differed across diagnostic groups. Multilevel modeling analyses indicated that perseverative errors (an index of reversal learning) predicted an increase in purging over time for individuals with AN-BP and BN. Set-shifting errors differentially predicted frequency of loss of control eating for individuals with AN-BP and BN; however, set-shifting was not related to loss of control eating when examined separately in AN-BP and BN. These findings suggest that disentangling facets of cognitive flexibility may help understand change in eating disorder symptoms.

The Efficacy of Cognitive Remediation Therapy for Anorexia Nervosa: A Systematic Review of Systematic Reviews

BACKGROUND

Cognitive remediation therapy (CRT) for anorexia nervosa (AN) is an intervention specifically focused on addressing cognitive difficulties associated with the eating disorder. This systematic review of systematic reviews and meta-analysis aimed to provide a summary of the existing literature examining the efficacy of CRT in improving the neuropsychological, psychological, and clinical parameters of patients with AN.

METHODS

Systematic reviews and meta-analyses were sought in electronic databases, encompassing studies that explored the impact of CRT on AN. Three eligible reviews were identified based on the inclusion criteria. The Revised Assessment of Multiple SysTemAtic Reviews (R-AMSTAR) was employed to evaluate the methodological quality of the reviews, and all included reviews demonstrated satisfactory methodological quality with an R-AMSTAR score of ≥22. Relevant information was extracted from each review and qualitatively compiled.

RESULTS

Findings suggest that CRT can help people increase their awareness of cognitive styles and information processing and have a positive effect on patients' responses to treatment.

CONCLUSIONS

Further research is required to better understand its impact on other relevant outcomes, including psychological variables, to optimize the treatment's benefits.

Expanding considerations for treating avoidant/restrictive food intake disorder at a higher level of care

Existing descriptions of the treatment of avoidant/restrictive food intake disorder (ARFID) at higher levels of care (HLOC) for eating disorders are limited, despite HLOC settings frequently serving patients with ARFID. The purpose of this commentary is to expand on the preliminary literature that describes pediatric ARFID treatment at HLOC by describing two specific components of our approach to treating pediatric ARFID that may not yet have traction in the current literature. Specifically, we highlight the utility of (1) treatment accommodations that appropriately account for patients' neurodevelopmental needs (e.g., executive functioning, sensory processing) and (2) the adjunctive use of Dialectical Behavior Therapy (DBT) elements within family-based pediatric ARFID treatment. We also describe necessary future directions for research in these domains to clarify if incorporating these considerations and approaches into pediatric ARFID treatment at HLOC does indeed improve treatment outcomes.

Exploring the intersection of autism spectrum disorder and eating disorders: understanding the unique challenges and treatment considerations for autistic women with eating disorders

PURPOSE OF REVIEW

Autistic women struggle with high levels of both autistic eating behaviours and disordered eating behaviours , which might make them particularly vulnerable to develop eating disorders. Research investigating the presence and characteristics of eating disorders in autistic women is however limited, as is research examining the role of autism in the treatment and recovery of an eating disorder in autistic women.

RECENT FINDINGS

The link between autism and eating disorders has mainly been investigated from the field of eating disorder research, with studies finding an overrepresentation of autism or autistic traits in eating disorders populations. Findings also suggest that autism or autistic traits are associated with a more serious presentation of the eating disorders, including a higher chance of a chronic course of the eating disorders. Most studies however lack comprehensive autism assessments, making it difficult to determine the actual prevalence of autism and its role in women with eating disorders.

SUMMARY

Autistic women with an eating disorder seem to suffer from more complex eating disorders and seem to not benefit from current treatment modalities. This could be partly related to specific autism characteristics such as sensory sensitivities, which are not being considered by current treatment protocols. Future research needs to shed light on what underlies the eating behaviours of autistic women with an eating disorder, in order to help to adapt current treatment modalities to meet the unique needs of these women.

Cognitive performance in hospitalized patients with severe or extreme anorexia nervosa

PURPOSE

Severe malnourishment may reduce cognitive performance in anorexia nervosa (AN). We studied cognitive functioning during intensive nutritional and medical stabilization in patients with severe or extreme AN and investigated associations between weight gain and cognitive improvement.

METHODS

A few days after admission to a specialized hospital unit, 33 patients with severe or extreme AN, aged 16-42 years, completed assessments of memory, cognitive flexibility, processing speed, and attention. Mean hospitalization was 6 weeks. Patients completed the same assessments at discharge (n = 22) following somatic stabilization and follow-up up to 6 months after discharge (n = 18).

RESULTS

The patients displayed normal cognitive performance at admission compared to normative data. During nutritional stabilization, body weight increased (mean: 11.3%; range 2.6-22.2%) and memory, attention, and processing speed improved (p values: ≤ 0.0002). No relationship between weight gain and cognitive improvement was observed at discharge or follow-up.

CONCLUSIONS

Cognitive performance at hospital admission was normal in patients with severe or extreme AN and improved during treatment although without association to weight gain. Based on these results, which are in line with previous studies, patients with severe or extreme AN need not be excluded from cognitively demanding tasks, possibly including psychotherapy. As patients may have other symptoms that interfere with psychotherapy, future research could investigate cognitive functioning in everyday life in patients with severe AN.

TRIAL REGISTRATION NUMBER

The study is registered at clinicaltrials.gov (NCT02502617).

LEVEL OF EVIDENCE

Level III, cohort study.

Psychotherapies for eating disorders: findings from a rapid review

BACKGROUND

Psychotherapy is considered central to the effective treatment of eating disorders-focusing on behavioural, psychological, and social factors that contribute to the illness. Research indicates psychotherapeutic interventions out-perform placebo, waitlist, and/or other treatments; but, outcomes vary with room for major improvement. Thus, this review aims to (1) establish and consolidate knowledge on efficacious eating disorder psychotherapies; (2) highlight select emerging psychotherapeutic interventions; and (3) identify knowledge gaps to better inform future treatment research and development.

METHODS

The current review forms part of a series of Rapid Reviews published in a special issue in the Journal of Eating Disorders to inform the development of the Australian-government-funded National Eating Disorder Research and Translation Strategy 2021-2031. Three databases were searched for studies published between 2009 and 2023, published in English, and comprising high-level evidence studies (meta-analyses, systematic reviews, moderately sized randomised controlled studies, moderately sized controlled-cohort studies, and population studies). Data pertaining to psychotherapies for eating disorders were synthesised and outlined in the current paper.

RESULTS

281 studies met inclusion criteria. Behavioural therapies were most commonly studied, with cognitive-behavioural and family-based therapies being the most researched; and thus, having the largest evidence-base for treating anorexia nervosa, bulimia nervosa, and binge eating disorder. Other therapies, such as interpersonal and dialectical behaviour therapies also demonstrated positive treatment outcomes. Emerging evidence supports specific use of Acceptance and Commitment; Integrative Cognitive Affective; Exposure; Mindfulness; and Emotionally-Focused therapies; however further research is needed to determine their efficacy. Similarly, growing support for self-help, group, and computer/internet-based therapeutic modalities was noted. Psychotherapies for avoidant/restrictive food intake disorder; other, and unspecified feeding and eating disorders were lacking evidence.

CONCLUSIONS

Currently, clinical practice is largely supported by research indicating that behavioural and cognitive-behavioural psychotherapies are most effective for the treatment of eating disorders. However, the efficacy of psychotherapeutic interventions varies across studies, highlighting the need for investment and expansion of research into enhanced variants and novel psychotherapies to improve illness outcomes. There is also a pressing need for investigation into the whole range of eating disorder presentations and populations, to determine the most effective interventions.

Exploring the role of autistic traits and eating disorder psychopathology on mentalising ability in the general population

BACKGROUND

This study evaluated the role of overlapping traits and characteristics related to autism spectrum disorder (autism) and anorexia nervosa (AN) in the general population, and the impact of these traits on mentalising ability.

METHODS

A sample of young adults (N = 306), aged 18-25 years, was recruited to complete an online study that consisted of 4 measures: the Autism-Spectrum Quotient, Eating Disorder Examination Questionnaire, the Mentalization Scale, and the Reading the Mind in the Eyes task.

RESULTS

Higher levels of autistic traits, particularly difficulty with attention switching, were associated with increased eating disorder psychopathology. Overall, autistic traits and eating disorder psychopathology were related among females, but not males. Difficulty with attention switching, however, was related to eating disorder psychopathology among both females and males. Autistic traits also appear to have a greater role in mentalising ability than does eating disorder psychopathology.

CONCLUSION

The role of attention switching in overlapping traits of autism and eating disorder psychopathology needs to be more comprehensively evaluated by future research, as does the role of biological sex. Expanded knowledge in this field will help to better understand and evaluate symptoms at presentation, leading to clearer diagnoses and potentially better treatment outcomes.

A randomized controlled feasibility trial of metacognitive training with adolescents receiving treatment for anorexia nervosa

OBJECTIVE

This pilot study investigated the feasibility and preliminary efficacy of the metacognitive training for eating disorders (MCT-ED) program in adolescents with anorexia nervosa (AN). We report attrition and subjective evaluation as well as changes to cognitive flexibility, perfectionism and eating disorder pathology relative to waitlist controls.

METHOD

Female (n = 35, aged 13-17 years) outpatients with a diagnosis of AN (n = 20) or atypical AN (n = 15) completed baseline measures of cognitive flexibility, perfectionism, and eating disorder pathology (May 2020-May 2022). Participants were randomly allocated to either treatment-as-usual (TAU) plus MCT-ED or TAU waitlist condition. All participants completed post-intervention and 3-month follow-up questionnaires.

RESULTS

The MCT-ED condition had a treatment attrition rate <15%. Participants provided positive evaluation of the program. There were large between groups differences favoring MCT-ED at post-intervention and 3-month follow-up for concern over mistakes perfectionism (respective ds = -1.25, 95% CI [-2.06, -.45]; -.83, 95% CI [-1.60, .06]) with a significant group difference post-intervention but not 3-month follow-up.

DISCUSSION

Findings provide tentative support for the feasibility of MCT-ED as an adjunct intervention for young people with AN, however replication is needed with a larger sample size to further explore its efficacy.

PUBLIC SIGNIFICANCE

Metacognitive training for eating disorders (MCT-ED) is a feasible adjunct intervention for adolescents with anorexia nervosa. The intervention, which targets thinking styles and is delivered online by a therapist, received positive feedback, had high treatment retention, and led to reductions in perfectionism by the end of treatment compared to wait-list controls. Although these gains were not sustained long-term, the program is suitable adjunct intervention for young people with eating disorders.

Emerging therapeutic targets for anorexia nervosa

INTRODUCTION

Anorexia nervosa is a frequent eating disorder that affects predominantly young women and may take a severe and chronically worsening course of disease contributing to its high mortality rate. Although a multitude of treatment options exist, this disease still bears a high relapse rate. In light of these facts, an improvement of existing and development of new treatment targets and options is warranted.

AREAS COVERED

The present review article covers recent developments in psychotherapy associated with the respective neuropsychological and brain alterations as well as highlights current and future pharmacotherapeutic options.

EXPERT OPINION

Several encouraging developments in the field of psychotherapy such as interventions targeting neurocognitive profiles or addressing reward processing, brain stimulation as well as pharmacological modulation of hormones, namely leptin, oxytocin, ghrelin and nesfatin-1 signaling might be - most likely as part of a multimodal treatment approach - efficacious in order to improve treatment of patients with anorexia nervosa, especially those with a severe course of disease as well as comorbidities. As anorexia nervosa represents a complex and severe mental disorder, it seems most likely that a combination and integration of different evidence-based treatment approaches and settings will contribute to an improved prognosis of this eating disorder. This should be further explored in future studies.

Sizing up the crowd: Assessing spatial integration difficulties in body size judgements across eating disorder symptomatology

Introduction

Body size judgements are frequently biased, or inaccurate, and these errors are further exaggerated for individuals with eating disorders. Within the eating disorder literature, it has been suggested that exaggerated errors in body size judgements are due to difficulties with integration. Across two experiments, we developed a novel integration task, named the Ebbinghaus Illusion for Bodies in Virtual Reality (VR), to assess whether nearby bodies influence the perceived size of a single body. VR was used to simulate the appearance of a small crowd around a central target body.

Method and Results

In Experiment 1 (N = 412), participants were required to judge the size of a central female target within a crowd. Experiment 1 revealed an Ebbinghaus Illusion, in which a central female appeared larger when surrounded by small distractors, but comparatively smaller when surrounded by large distractors. In other words, the findings of Experiment 1 demonstrate that surrounding crowd information is integrated when judging an individual's body size; a novel measure of spatial integration (i.e., an Ebbinghaus Illusion for Bodies in VR). In Experiment 2 (N = 96), female participants were selected based on high (n = 43) and low (n = 53) eating disorder symptomatology. We examined whether the magnitude of this illusion would differ amongst those with elevated versus low eating disorder symptomatology, in accordance with weak central coherence theory, with the high symptomatology group displaying less spatial integration relative to the low group. The results of Experiment 2 similarly found an Ebbinghaus Illusion for Bodies in VR. However, illusion magnitude did not vary across high and low symptomatology groups.

Discussion

Overall, these findings demonstrate that surrounding crowd information is integrated when judging individual body size; however, those with elevated eating disorder symptomatology did not show any integration deficit on this broader measure of spatial integration.

Therapeutic uses of psychedelics for eating disorders and body dysmorphic disorder

BACKGROUND

Clinical use of psychedelics has gained considerable attention, with promising benefits across a range of mental disorders. Current pharmacological and psychotherapeutic treatments for body dysmorphic disorder (BDD) and eating disorders (EDs) have limited efficacy. As such, other treatment options such as psychedelic-assisted therapies are being explored in these clinical groups.

AIMS

This systematic review evaluates evidence related to the therapeutic potential of psychedelics in individuals diagnosed with BDD and EDs.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic review of all study designs published to the end of February 2022 that identified changes in ED/BDD symptom severity from psychedelics using validated measures to assess symptom changes.

RESULTS

Our search detected a total of 372 studies, of which five met inclusion criteria (two exploratory studies, two case reports, and one prospective study). These were included in the data evaluation. Effects of psychedelics on BDD and various ED symptoms were identified mostly through thematic analyses and self-reports.

CONCLUSIONS

Our findings highlight that more research is needed to determine the safety and efficacy of psychedelics in BDD and EDs and we suggest avenues for future exploration.

An exploratory examination of executive functioning as an outcome, moderator, and predictor in outpatient treatment for adults with anorexia nervosa

OBJECTIVE

People with anorexia nervosa often exhibit inefficiencies in executive functioning (central coherence and set shifting) that may negatively impact on treatment outcomes. It is unclear from previous research whether these inefficiencies can change over treatment. We aimed to (1) investigate whether executive functioning can improve over treatment, (2) determine whether baseline executive functioning moderates treatment outcome, and (3) examine whether baseline executive functioning predicts early change (i.e., increase in body mass index over the first 13 weeks of treatment) or remission.

METHOD

We conducted linear mixed model and logistic regression analyses on data from the Strong Without Anorexia Nervosa trial (Byrne et al. in Psychol Med 47:2823-2833, 2017). This study was a randomised controlled trial of three outpatient treatments for people with anorexia nervosa: Enhanced Cognitive Behavioural Therapy, Maudsley Model Anorexia Nervosa Treatment for Adults, and Specialist Supportive Clinical Management.

RESULTS

While set shifting clearly improved from baseline to end of treatment, the results for central coherence were less clear cut. People with low baseline central coherence had more rapid reductions in eating disorder psychopathology and clinical impairment than those with high baseline central coherence. Baseline executive functioning did not predict early change or remission.

DISCUSSION

The detail-focused thinking style commonly observed among people with anorexia nervosa may aid treatment outcomes. Future research that is more adequately powered should replicate this study and examine whether the same pattern of results is observed among people with non-underweight eating disorders.

Randomized controlled trial of cognitive remediation therapy in adolescent inpatients with anorexia nervosa: Neuropsychological outcomes

OBJECTIVE

Neuropsychological dysfunction exists in anorexia nervosa (AN). Cognitive Remediation Therapy (CRT), mainly evaluated in adults with AN, targets these impairments.

METHODS

Adolescent inpatients (age = 11-17 years) with AN were randomized to 5 weeks of either 10 sessions of individually delivered CRT or non-specific cognitive-training (NSCT). Co-primary outcomes included cognitive domain 'flexibility' [composite score of Wisconsin Card Sorting Test (WSCT) and Trail Making Test (TMT-4)] and 'central coherence' [composite score of Central Coherence Index (CCI) and Group Embedded Figures Test (GEFT)] at end of treatment (FU1). Secondary outcomes included individual test scores and self-reported everyday-life flexibility at FU1 and at 6-months post-treatment (FU2). Independent sample t-tests, Pearson chi-square-tests and mixed models for repeated measures (MMRM) analyses were conducted.

RESULTS

In 56 females (age = 15.1 ± 1.5 years), CRT was not superior to NSCT at FU1 regarding 'flexibility' (p = 0.768) or 'central coherence' (p = 0.354), nor at FU2 (p = 0.507; p = 0.624) (effect sizes = 0.02-0.26). Both groups improved over time in central coherence (CCI p = 0.001; GEFT p < 0.001), self-reported flexibility (p = 0.002) and WCST (p = 0.18), but not TMT-4 (p = 0.286). NSCT was superior to CRT regarding self-reported planning/organisation ability at FU1 (p < 0.001) and FU2 (p = 0.003).

CONCLUSIONS

CRT was not superior to NSCT in adolescent inpatients with AN. More randomized controlled studies are needed.

Eye movements and eating disorders: protocol for an exploratory experimental study examining the relationship in young-adult women with subclinical symptomatology

BACKGROUND

Recent research indicates that patients with anorexia (AN) show specific eye movement abnormalities such as shorter prosaccade latencies, more saccade inhibition errors, and increased rate of saccadic intrusions compared to participants without AN. However, it remains unknown whether these abnormal eye movement patterns, which may serve as potential biomarkers and endophenotypes for an early diagnosis and preventive clinical treatments, start to manifest also in people with subclinical eating disorders (ED) symptomatology. Therefore, we propose a protocol for an exploratory experimental study to investigate whether participants with subclinical ED symptomatology and control participants differ in their performance on several eye movement tasks.

METHODS

The sample will be recruited through convenience sampling. The Eating Disorder Examination Questionnaire will be administered as a screening tool to split the sample into participants with subclinical ED symptomatology and control participants. A fixation task, prosaccade/antisaccade task, and memory-guided task will be administered to both groups. Additionally, we will measure anxiety and premorbid intelligence as confounding variables. Means comparison, exploratory Pearson's correlations and discriminant analysis will be performed.

DISCUSSION

This study will be the first to elucidate the presence of specific eye movement abnormalities in participants with subclinical ED symptomatology. The results may open opportunities for developing novel diagnostic tools/therapies being helpful to the EDs research community and allied fields.

Olfactory capacity in anorexia nervosa: correlations with set-shifting ability

PURPOSE

The purpose of this study is to examine olfactory capacity in adults with anorexia nervosa (AN), in terms of odor identification and odor threshold and search for possible correlations between odor identification and cognitive flexibility in this population.

METHODS

Thirty-nine patients diagnosed with AN and 60 healthy participants, participated. Odor identification was assessed using the University Pennsylvania Smell Identification Test and a two alternative forced choice, ascending method with n-butanol was used to assess odor threshold. Cognitive flexibility was determined using the Intra/Extra-Dimensional Set-Shift test (IED), a subtest of the Cambridge Neuropsychological Test Automated Battery (CANTAB).

RESULTS

Patients with AN presented a poorer performance in odor identification compared with controls (p = 0.001). No differences were found in odor threshold, between the two groups. Patients with AN exhibited poor cognitive flexibility compared with controls (p = 0.003). A significant correlation between odor identification and cognitive flexibility was documented in AN (p = 0.01), but not in controls.

CONCLUSION

Our findings suggest that olfactory capacity is altered in AN: Qualitative characteristics of olfaction were affected in patients with AN (lower odor identification), while there was no difference in quantitative characteristics (odor threshold) compared with controls. Furthermore, odor identification in AN was correlated to cognitive flexibility.

LEVEL OF EVIDENCE

Level III: case-control analytic study.

Cognitive flexibility and attention to detail in adolescents and adults with severe forms of anorexia nervosa

OBJECTIVE

To determine if adolescents and adults diagnosed with anorexia nervosa differ in their levels of cognitive flexibility and attention to detail independently of potential confounds.

METHOD

Sixty-two adolescents and 54 adults were assessed while receiving inpatient treatment and completed the following self-reports: Eating Disorders Examination Questionnaire, Maudsley Obsessive Compulsive Inventory and Hospital Anxiety and Depression scale. Performance-based evaluations included the Wisconsin Card Sorting Test Computerised Version, the Comprehensive Trail Making Test, the Brixton Spatial Anticipation Test, the Rey Complex Figure and the Group Embedded Figures Test.

RESULTS

Comparisons of the adolescents and adults with anorexia nervosa revealed no significant differences for any of the neuropsychological test scores even after adjusting for potential confounding factors. Neither cognitive flexibility nor attention to detail were associated with level of eating disorder symptomatology, depression, anxiety or obsessive-compulsive symptomatology. Unlike age, illness duration was found weakly associated with perseverative errors Wisconsin Card Sorting Test and with the central coherence index of the Rey Complex Figure recall condition.

CONCLUSIONS

Set-shifting and central coherence performance were independent of age, clinical symptoms severity and emotional status. Additional studies on the relationship between the duration of anorexia nervosa and neuropsychological difficulties are needed.

Cognitive flexibility, central coherence, and quality of life in anorexia nervosa

BACKGROUND

Anorexia nervosa (AN) has consistently been found to be associated with poor cognitive flexibility and central coherence. These two cognitive functions have been considered important maintenance factors in AN and are addressed by specific treatment approaches such as cognitive remediation therapy. While there is clear empirical evidence that difficulties in such cognitive functions are related to impaired daily functioning in schizophrenia and bipolar disorder, this potential association has received only little attention in AN research so far. Therefore, the aim of this study was to examine potential relationships between weak cognitive flexibility, central coherence, and poor quality of life (QoL) in AN.

METHODS

Cognitive flexibility and central coherence were measured by both neuropsychological (i.e., performance based) and self-report measures alongside with self-reported QoL in a sample of 138 adult patients with AN.

RESULTS

Self-report but not performance based measures of cognitive flexibility and central coherence were associated with QoL. Weaker cognitive flexibility and central coherence were correlated with poorer QoL. These associations were independent of comorbid depression. The link between weak central coherence and poor QoL was particularly strong in patients with the restricting subtype of AN. The link between cognitive flexibility and QoL, however, was independent of AN subtype.

CONCLUSIONS

Weak cognitive flexibility and central coherence are associated with low QoL in AN, especially in patients with the restrictive subtype. However, this relationship is dependent on the method of measurement, where self-report measures seem to be more relevant than performance based measures.

Cognitive and Experienced Flexibility in Patients With Anorexia Nervosa and Obsessive Compulsive Disorder

OBJECTIVE

Anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) share a neuropsychological profile characterized by cognitive inflexibility as evident in set-shifting problems, and by strong detail focus. Clinically, both patient groups display a strong rigidity which may be explained by these neurocognitive difficulties. Cognitive inflexibility may hinder treatment uptake and help explain suboptimal treatment outcomes in both AN and OCD. This is the first study to compare clinical AN and OCD groups andto examine similarities and differences in cognitive flexibility. Specifically, this study aims to investigate neuropsychological outcomes and self-reported difficulties in both clinical groups and a control group, and explore associations between the different flexibility outcomes and illness.

METHOD

Two hundred participants (61 AN, 72 OCD and 67 HC) performed neuropsychological tasks on set-shifting abilities (Trail Making Task, Stroop color-word interference, Intradimensional-Extradimensional shift task), detail focus (Group Embedded Figures Test) and self-reported set-shifting abilities and attention to detail (DFlex).

RESULTS

Similarities between patient groups were found in terms of reduced set-shifting ability on the Trail Making Task and detail focus. Moreover, both patient groups self-reported more set-shifting problems but a less strong detail focus than HC, which in turn were not related to neuropsychological task outcomes in either of the groups. In both patient groups longer illness duration was associated to longer reaction times in the switching tasks and for both groups symptom severity was associated to higher experienced inflexibility and attention to detail.

CONCLUSION

Cognitive inflexibility processes are largely similar in patients with AN and OCD. Both patient groups report inflexibility, yet this is unrelated to neuropsychological outcomes. Illness duration seems to contribute to poorer set-shifting and higher illness severity is linked to more experienced inflexibility. Findings highlight the need for entangling different domains of cognitive flexibility and detail focus and examining self-report measures for a cohesive understanding of clinically relevant flexibility weaknesses in AN and OCD.

Beyond Description and Deficits: How Computational Psychiatry Can Enhance an Understanding of Decision-Making in Anorexia Nervosa

PURPOSE OF REVIEW

Despite decades of research, knowledge of the mechanisms maintaining anorexia nervosa (AN) remains incomplete and clearly effective treatments elusive. Novel theoretical frameworks are needed to advance mechanistic and treatment research for this disorder. Here, we argue the utility of engaging a novel lens that differs from existing perspectives in psychiatry. Specifically, we argue the necessity of expanding beyond two historically common perspectives: (1) the descriptive perspective: the tendency to define mechanisms on the basis of surface characteristics and (2) the deficit perspective: the tendency to search for mechanisms associated with under-functioning of decision-making abilities and related circuity, rather than problems of over-functioning, in psychiatric disorders.

RECENT FINDINGS

Computational psychiatry can provide a novel framework for understanding AN because this approach emphasizes the role of computational misalignments (rather than absolute deficits or excesses) between decision-making strategies and environmental demands as the key factors promoting psychiatric illnesses. Informed by this approach, we argue that AN can be understood as a disorder of excess goal pursuit, maintained by over-engagement, rather than disengagement, of executive functioning strategies and circuits. Emerging evidence suggests that this same computational imbalance may constitute an under-investigated phenotype presenting transdiagnostically across psychiatric disorders. A variety of computational models can be used to further elucidate excess goal pursuit in AN. Most traditional psychiatric treatments do not target excess goal pursuit or associated neurocognitive mechanisms. Thus, targeting at the level of computational dysfunction may provide a new avenue for enhancing treatment for AN and related disorders.

Anorexia nervosa and comorbid autism spectrum disorders

PURPOSE OF REVIEW

Traits of autism spectrum disorder (ASD) are overrepresented among individuals with anorexia nervosa (AN) and may also moderate the behavioral manifestation of AN. This review aims to provide an overview of AN and comorbid ASD.

RECENT FINDINGS

Elevated ASD traits do not seem to precede AN among some individuals but are rather related to the illness stage. However, studies have suggested that there are ASD-specific mechanisms for developing AN in a subgroup of individuals with AN. Pronounced traits of ASD and diagnosed ASD are associated with illness prolongation and poorer outcomes in AN, and individuals with AN and elevated ASD traits may benefit less from many of the current treatments. Studies do not support a specific genetic relationship between ASD and AN.

SUMMARY

Recent research encourages the improved recognition of elevated ASD traits in individuals with AN and provides grounds for developing tailored treatments for those with this comorbidity.

Study Protocol for "Psilocybin as a Treatment for Anorexia Nervosa: A Pilot Study"

Background: Anorexia nervosa (AN) is a serious and life-threatening psychiatric condition. With a paucity of approved treatments, there is a desperate need for novel treatment avenues to be explored. Here, we present (1) an overview of the ways through which Public Patient Involvement (PPI) has informed a trial of psilocybin-assisted therapy for AN and (2) a protocol for a pilot study of psilocybin-assisted therapy in AN currently underway at Imperial College London. The study aims to assess the feasibility, brain mechanisms and preliminary outcomes of treating anorexia nervosa with psilocybin. Methods: (1) PPI: Across two online focus groups, eleven individuals with lived experience of AN were presented with an overview of the protocol. Their feedback not only identified solutions to possible barriers for future participants, but also helped the research team to better understand the concept of "recovery" from the perspective of those with lived experience. (2) Protocol: Twenty female participants [21-65 years old, body mass index (BMI) 15 kg/m2 or above] will receive three oral doses of psilocybin (up to 25 mg) over a 6-week period delivered in a therapeutic environment and enveloped by psychological preparation and integration. We will work with participant support networks (care teams and an identified support person) throughout and there will be an extended remote follow-up period of 12 months. Our two-fold primary outcomes are (1) psychopathology (Eating Disorder Examination) across the 6-month follow-up and (2) readiness and motivation to engage in recovery (Readiness and Motivation Questionnaire) across the 6-week trial period. Neurophysiological outcome measures will be: (1) functional magnetic resonance imaging (fMRI) brain changes from baseline to 6-week endpoint and (2) post-acute changes in electroencephalography (EEG) activity, including an electrophysiological marker of neuronal plasticity. Discussion: The results of this pilot study will not only shed light on the acceptability, brain mechanisms, and impression of the potential efficacy of psilocybin as an adjunct treatment for AN but will be essential in shaping a subsequent Randomised Control Trial (RCT) that would test this treatment against a suitable control condition. Clinical Trial Registration: identifier: NCT04505189.

[Eating and feeding disorders : New developments]

An overview of eating and feeding disorders according to the future criteria of the International Classification of Diseases (ICD-11) is presented, including information on differential diagnosis, epidemiology, etiology, pathogenesis as well as therapy. Binge-eating disorder is new and the most frequent eating disorder. While anorexia nervosa and bulimia nervosa mostly affect women, the gender ratio in binge-eating disorder is more balanced. Concerning etiology, socio-cultural, biological and psychological factors are discussed. Cognitive behavioral psychotherapy is the best-validated treatment for all three eating disorders. According to the German guidelines for treatment (2019), focal psychodynamic psychotherapy is also a treatment option for anorexia nervosa. Evidence for the positive effect of psychopharmacologic drugs in the treatment of anorexia nervosa is still lacking. Fluoxetine has been shown to have a limited effect in the treatment of bulimia nervosa.

Cognitive remediation therapy for anorexia nervosa as a rolling group intervention: Data from a longitudinal study in an eating disorders specialized inpatient unit

Objective

Cognitive remediation therapy (CRT) has been proposed as an add‐on treatment approach that could increase the engagement in treatment of anorexia nervosa (AN) patients and reduce maintaining factors, but prior studies have evaluated CRT in individual and group settings, difficult protocols for rehabilitation settings. Our aim is to evaluate the CRT rolling protocol implementation in an inpatient specialised unit.

Methods

A historical longitudinal controlled study was designed to include 31 AN patients for the CRT program, and 28 AN patients treated as usual. The CRT rolling group was implemented in a multidisciplinary inpatient rehabilitation ward with both adolescent and adult patients and an 8‐weeks protocol. To evaluate the treatment implementation effect, different self‐administered questionnaires were used.

Results

The study found greater improvements of the CRT group in clinical symptomatology (p = 0.039), flexibility (p = 0.003), self‐confidence about the ability to change (p < 0.001), and less short‐term focus (p < 0.001), with no differences between restrictive and binge‐purging patients.

Conclusion

This study demonstrates that CRT rolling group protocol is feasible in an inpatient treatment setting and may improve a rehabilitation program's outcome. Our results have shown how CRT can influence cognitive styles considered AN maintenance factors, positively affecting both restrictive and binge‐purge type.

Cognitive remediation therapy (CRT) could be implemented in an inpatient setting with a rolling protocol

CRT improves flexibility, drive to change, and therapy engagement

No differences between restrictive or binge/purge subgroups

Both adolescent and adult patients improved their cognitive styles

Adapting a neuroscience-informed intervention to alter reward mechanisms of anorexia nervosa: a novel direction for future research

Accumulating psychobiological data implicate reward disturbances in the persistence of anorexia nervosa (AN). Evidence suggests that individuals with AN demonstrate decision-making deficits similar to those with mood and anxiety disorders that cause them to under-respond to many conventionally rewarding experiences (e.g., eating, interacting socially). In contrast, unlike individuals with other psychiatric disorders, individuals with AN simultaneously over-respond to rewards associated with eating-disorder behaviors (e.g., restrictive eating, exercising). This pattern of reward processing likely perpetuates eating-disorder symptoms, as the rewards derived from eating-disorder behaviors provide temporary relief from the anhedonia associated with limited responsivity to other rewards. Positive Affect Treatment (PAT) is a cognitive-behavioral intervention designed to target reward deficits that contribute to anhedonia in mood and anxiety disorders, including problems with reward anticipation, experiencing, and learning. PAT has been found to promote reward responsivity and clinical improvement in mood and anxiety disorders. This manuscript will: (1) present empirical evidence supporting the promise of PAT as an intervention for AN; (2) highlight nuances in the maintaining processes of AN that necessitate adaptations of PAT for this population; and (3) suggest future directions in research on PAT and other reward-based treatments that aim to enhance clinical outcomes for AN.

Increased cognitive flexibility mediates the improvement of eating disorders symptoms, depressive symptoms and level of daily life functioning in patients with anorexia nervosa treated in specialised centres

OBJECTIVE

Poor cognitive flexibility has been highlighted in patients with anorexia nervosa (AN), contributing to the development and maintenance of symptoms. The aim of the present study is to investigate how enhanced cognitive flexibility is involved in treatment outcomes in patients with AN.

METHOD

One hundred thirty female out-patients treated for AN have been assessed at baseline and after 4 months of treatment. Path analyses were used to investigate the mediating role of cognitive flexibility, measured through the Brixton test, on a wide range of outcomes: body mass index, eating disorder symptoms, daily life functioning, anxiety, depression, emotions, self-rated silhouette.

RESULTS

Cognitive flexibility was improved during treatment, and enhanced cognitive flexibility explains a significant part of level of the improvement in daily life functioning (26%), reduction of eating disorder symptoms (18%) and reduction of depressive symptoms (17%). Others outcomes were also improved, but these improvements were not mediated by cognitive flexibility.

CONCLUSIONS

Results suggest that enhancing cognitive flexibility could help reduce rigid cognitive and behavioural patterns involved in AN, thus improving everyday functioning and clinical severity. Further studies combining different types of cognitive flexibility evaluation as well as neuroimaging may be necessary to better establish which of its aspects are involved in patients' improvement.

Cognitive Function in Adults with Enduring Anorexia Nervosa

Anorexia Nervosa (AN) is a severe and often enduring disorder characterized by restriction of food intake, low body weight, fear of weight gain, and distorted body image. Investigations on cognition performance in AN patients have yielded conflicting results. Using an established and sensitive computerized cognitive test battery, we aimed to assess core aspects of cognitive function, including attention span, information processing, reasoning, working and episodic memory, in AN patients and controls. Patients were recruited from the Danish Prospective Longitudinal all-comer inclusion study in Eating Disorders (PROLED). Included were 26 individuals with AN and 36 healthy volunteers (HV). All were tested with CogTrack (an online cognitive assessment system) at baseline, and AN patients were tested again at a follow-up time point after weight increase (n = 13). At baseline, AN patients showed faster reaction times in the attention tasks, as well as increased accuracy in grammatical reasoning compared to HV. There were no differences in cognitive function between AN patients and HV in the other cognitive domains measured (sustained attention, working and episodic memory, speed of retrieval, and speed of grammatical reasoning). No differences were visible in the AN sample between baseline and follow-up. Performance did not correlate with any clinical variables in the AN sample. These findings supplement results from other studies suggesting increased concentration and reasoning accuracy in patients suffering from AN, who showed increased performance in cognitive tasks despite their illness.

Effects of Hormonal Contraception Use on Cognitive Functions in Patients With Bulimia Nervosa

Background: Growing evidences indicate that sex hormones have an effect on cognitive functions, and that Bulimia Nervosa (BN) is associated with cognitive impairment. The aim of this study was to determine the effect of hormonal contraception (HC) use on four cognitive functions that are impaired in patients with BN. Methods: This retrospective exploratory study included 103 women with a diagnosis of BN based on the DSM-5 criteria. Their age ranged from 15 to 45 years, and 46.6% were taking HC (oral, transdermal, or intrauterine). Cognition was assessed with the d2 test (attention), Iowa gambling task (IGT; decision making), Brixton spatial anticipation test (set shifting), and Rey-Osterrieth complex figure test (central coherence). Data were analyzed with logistic regression models to estimate the adjusted odds ratios (OR) and 95% confidence intervals (CI) of HC effect on the neuropsychological test scores. Results: In the multivariate model, HC use was significantly associated with better scores for two d2 test indices: F-score [OR = 0.98, 95% CI = (0.95; 0.99)] and final total score ratio [OR = 0.87, 95% CI = (0.77; 0.99)]. HC was also associated with a better understanding of the IGT explicit rules. No difference between the two groups (HC and non-HC use) was detected for set shifting and central coherence. Conclusions: This exploratory study suggests that HC could have effects on the sustained attention and concentration in women with BN. More studies are needed to confirm these results.